The price difference between the average first-time buyer property and homes suitable for second steppers has more than doubled since the last financial crisis, research by modular housebuilder Project Etopia suggests.

The gap between the price of an average flat and a terraced house in the UK has increased from £20,744 to £49,916 since 2008 according to the developer’s analysis.

The research, which looked at current average prices across 100 major UK towns and cities, revealed why many families are struggling to upsize from a starter home to a larger three or four-bedroom property.

The average price of a flat was £145,276 compared to £195,191 for a terraced house, a difference in price of 34.4 per cent.

If the gap continues to widen at its current rate, within the next decade second steppers will face a price jump of more than £100,000 in order to upsize.

The research found some parts of the UK offer a much easier step up to the second rung of the ladder.

The North West has four of the five most accessible cities for second steppers.

Manchester has the smallest gap between rungs, as the average price of a flat is £164,188 and the average price of a terraced house is £171,286 – a difference of less than £10,000 or 4.1 per cent.

In Liverpool, Salford, Nottingham and Oldham the cost jump from a flat to a house was between 7 and 11.5 per cent.

At the other end of the scale in the South East, the increase in the cost from buying a flat to a house in Luton is 56.8 per cent and in Hastings it is 54.8 per cent.

Project Etopia chief executive Joseph Daniels says: “There’s a potential housing crisis brewing which could damage the UK property market irreparably if it’s not addressed.

“The government has trumpeted its commitment to supporting first-time buyers, but it seems once you are on the housing ladder you’re basically on your own. 

“We are told how difficult it is to purchase your first property, but many discover once they’re on the ladder, making the next step up is more problematic. 

“The lack of three and four-bed family properties coming onto the market has seen the price gap between starter homes and family houses widen over the past decade. 

“New family homes are not being built fast enough to increase stock levels, leaving many second steppers unable to upsize and forced to remain in smaller properties, living under cramped and unacceptable conditions.”